Greenberg: This Market's the Greater Fool Theory

Herb says, the out-of-whack valuations of cult stocks make his stomach turn.

To which I wanted to scream in 140 characters or less: No, pal, price is nothing more than a number.

Jim gets the concept that, at these prices, many investors (all but those who genuinely think they're geniuses who are beating the house) are holding their nose when they buy.

In an email exchange last night, I told him: "These stocks are high-wire acts."

He to me: "I love a high wire act."

Me to he: "So do I, believe it or not. I got to know Karl Wallenda before he died -- pushed off the wire by a gust of wind in Puerto Rico! This market is like that -- waiting for a gust of wind."

That's why, as I mentioned to Jim last night, I call this is greater fool theory kind of market.

Cramer to me: "How about the smarter fool theory?"

Me to he: "Classic Cramer."

Reality: All of these stocks have melted up because of short squeezes, momentum gone wild or just good old-fashioned fears of missing the out on all of the fun. We've seen this before. We know how it ends. Until then, make sure you appoint a designated driver.

Herb Greenberg, editor of Herb Greenberg's Reality Check, is a contributor to CNBC. He does not own shares, short or trade shares in an individual corporate security.